Fix and assert getLocalFunction invariant

pkg/compiler/lib/src/ssa/builder_kernel.dart

Index: pkg/compiler/lib/src/ssa/builder_kernel.dart
diff --git a/pkg/compiler/lib/src/ssa/builder_kernel.dart b/pkg/compiler/lib/src/ssa/builder_kernel.dart
index d97fe22aaa4c95a60c2667a3c3d337f01869ed55..d8bf389c78644c63550203e3249d39beb1b46133 100644
--- a/pkg/compiler/lib/src/ssa/builder_kernel.dart
+++ b/pkg/compiler/lib/src/ssa/builder_kernel.dart
@@ -2944,7 +2944,7 @@ class KernelSsaGraphBuilder extends ir.Visitor
 
   @override
   visitFunctionNode(ir.FunctionNode node) {
-    Local methodElement = _elementMap.getLocalFunction(node);
+    Local methodElement = _elementMap.getLocalFunction(node.parent);
     ClosureRepresentationInfo closureInfo =
         closureDataLookup.getClosureRepresentationInfo(methodElement);
     ClassEntity closureClassEntity = closureInfo.closureClassEntity;
@@ -2965,7 +2965,7 @@ class KernelSsaGraphBuilder extends ir.Visitor
   visitFunctionDeclaration(ir.FunctionDeclaration declaration) {
     assert(isReachable);
     declaration.function.accept(this);
-    Local localFunction = _elementMap.getLocalFunction(declaration.function);
+    Local localFunction = _elementMap.getLocalFunction(declaration);
     localsHandler.updateLocal(localFunction, pop());
   }